Currently, a dual microphone noise reduction technology is used for most mobile terminals in the market. Dual microphone noise reduction means that two microphones are built in a handset, one for clear voice communication and the other for active physical noise reduction where ambient sounds are collected and processed and then a sound wave with an inverted phase to the noise is generated to reduce the noise by using an offsetting principle.
Due to the size of the mobile terminal, it is impossible to place a noise reduction microphone far from a main microphone. Therefore, when noise is filtered, some useful sounds are also filtered, thereby affecting the quality of voice communication and weakening the effect of noise reduction.